1*0Sstevel@tonic-gate /*
2*0Sstevel@tonic-gate * Copyright (c) 2000 Niels Provos. All rights reserved.
3*0Sstevel@tonic-gate * Copyright (c) 2001 Markus Friedl. All rights reserved.
4*0Sstevel@tonic-gate *
5*0Sstevel@tonic-gate * Redistribution and use in source and binary forms, with or without
6*0Sstevel@tonic-gate * modification, are permitted provided that the following conditions
7*0Sstevel@tonic-gate * are met:
8*0Sstevel@tonic-gate * 1. Redistributions of source code must retain the above copyright
9*0Sstevel@tonic-gate * notice, this list of conditions and the following disclaimer.
10*0Sstevel@tonic-gate * 2. Redistributions in binary form must reproduce the above copyright
11*0Sstevel@tonic-gate * notice, this list of conditions and the following disclaimer in the
12*0Sstevel@tonic-gate * documentation and/or other materials provided with the distribution.
13*0Sstevel@tonic-gate *
14*0Sstevel@tonic-gate * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
15*0Sstevel@tonic-gate * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
16*0Sstevel@tonic-gate * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
17*0Sstevel@tonic-gate * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
18*0Sstevel@tonic-gate * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
19*0Sstevel@tonic-gate * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
20*0Sstevel@tonic-gate * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
21*0Sstevel@tonic-gate * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
22*0Sstevel@tonic-gate * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
23*0Sstevel@tonic-gate * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
24*0Sstevel@tonic-gate */
25*0Sstevel@tonic-gate
26*0Sstevel@tonic-gate #include "includes.h"
27*0Sstevel@tonic-gate RCSID("$OpenBSD: kexgex.c,v 1.22 2002/03/24 17:27:03 stevesk Exp $");
28*0Sstevel@tonic-gate
29*0Sstevel@tonic-gate #pragma ident "%Z%%M% %I% %E% SMI"
30*0Sstevel@tonic-gate
31*0Sstevel@tonic-gate #include <openssl/bn.h>
32*0Sstevel@tonic-gate
33*0Sstevel@tonic-gate #include "xmalloc.h"
34*0Sstevel@tonic-gate #include "buffer.h"
35*0Sstevel@tonic-gate #include "bufaux.h"
36*0Sstevel@tonic-gate #include "key.h"
37*0Sstevel@tonic-gate #include "kex.h"
38*0Sstevel@tonic-gate #include "log.h"
39*0Sstevel@tonic-gate #include "packet.h"
40*0Sstevel@tonic-gate #include "dh.h"
41*0Sstevel@tonic-gate #include "ssh2.h"
42*0Sstevel@tonic-gate #include "compat.h"
43*0Sstevel@tonic-gate
44*0Sstevel@tonic-gate u_char *
kexgex_hash(char * client_version_string,char * server_version_string,char * ckexinit,int ckexinitlen,char * skexinit,int skexinitlen,u_char * serverhostkeyblob,int sbloblen,int min,int wantbits,int max,BIGNUM * prime,BIGNUM * gen,BIGNUM * client_dh_pub,BIGNUM * server_dh_pub,BIGNUM * shared_secret)45*0Sstevel@tonic-gate kexgex_hash(
46*0Sstevel@tonic-gate char *client_version_string,
47*0Sstevel@tonic-gate char *server_version_string,
48*0Sstevel@tonic-gate char *ckexinit, int ckexinitlen,
49*0Sstevel@tonic-gate char *skexinit, int skexinitlen,
50*0Sstevel@tonic-gate u_char *serverhostkeyblob, int sbloblen,
51*0Sstevel@tonic-gate int min, int wantbits, int max, BIGNUM *prime, BIGNUM *gen,
52*0Sstevel@tonic-gate BIGNUM *client_dh_pub,
53*0Sstevel@tonic-gate BIGNUM *server_dh_pub,
54*0Sstevel@tonic-gate BIGNUM *shared_secret)
55*0Sstevel@tonic-gate {
56*0Sstevel@tonic-gate Buffer b;
57*0Sstevel@tonic-gate static u_char digest[EVP_MAX_MD_SIZE];
58*0Sstevel@tonic-gate const EVP_MD *evp_md = EVP_sha1();
59*0Sstevel@tonic-gate EVP_MD_CTX md;
60*0Sstevel@tonic-gate
61*0Sstevel@tonic-gate buffer_init(&b);
62*0Sstevel@tonic-gate buffer_put_cstring(&b, client_version_string);
63*0Sstevel@tonic-gate buffer_put_cstring(&b, server_version_string);
64*0Sstevel@tonic-gate
65*0Sstevel@tonic-gate /* kexinit messages: fake header: len+SSH2_MSG_KEXINIT */
66*0Sstevel@tonic-gate buffer_put_int(&b, ckexinitlen+1);
67*0Sstevel@tonic-gate buffer_put_char(&b, SSH2_MSG_KEXINIT);
68*0Sstevel@tonic-gate buffer_append(&b, ckexinit, ckexinitlen);
69*0Sstevel@tonic-gate buffer_put_int(&b, skexinitlen+1);
70*0Sstevel@tonic-gate buffer_put_char(&b, SSH2_MSG_KEXINIT);
71*0Sstevel@tonic-gate buffer_append(&b, skexinit, skexinitlen);
72*0Sstevel@tonic-gate
73*0Sstevel@tonic-gate buffer_put_string(&b, serverhostkeyblob, sbloblen);
74*0Sstevel@tonic-gate if (min == -1 || max == -1)
75*0Sstevel@tonic-gate buffer_put_int(&b, wantbits);
76*0Sstevel@tonic-gate else {
77*0Sstevel@tonic-gate buffer_put_int(&b, min);
78*0Sstevel@tonic-gate buffer_put_int(&b, wantbits);
79*0Sstevel@tonic-gate buffer_put_int(&b, max);
80*0Sstevel@tonic-gate }
81*0Sstevel@tonic-gate buffer_put_bignum2(&b, prime);
82*0Sstevel@tonic-gate buffer_put_bignum2(&b, gen);
83*0Sstevel@tonic-gate buffer_put_bignum2(&b, client_dh_pub);
84*0Sstevel@tonic-gate buffer_put_bignum2(&b, server_dh_pub);
85*0Sstevel@tonic-gate buffer_put_bignum2(&b, shared_secret);
86*0Sstevel@tonic-gate
87*0Sstevel@tonic-gate #ifdef DEBUG_KEXDH
88*0Sstevel@tonic-gate buffer_dump(&b);
89*0Sstevel@tonic-gate #endif
90*0Sstevel@tonic-gate EVP_DigestInit(&md, evp_md);
91*0Sstevel@tonic-gate EVP_DigestUpdate(&md, buffer_ptr(&b), buffer_len(&b));
92*0Sstevel@tonic-gate EVP_DigestFinal(&md, digest, NULL);
93*0Sstevel@tonic-gate
94*0Sstevel@tonic-gate buffer_free(&b);
95*0Sstevel@tonic-gate
96*0Sstevel@tonic-gate #ifdef DEBUG_KEXDH
97*0Sstevel@tonic-gate dump_digest("hash", digest, EVP_MD_size(evp_md));
98*0Sstevel@tonic-gate #endif
99*0Sstevel@tonic-gate return digest;
100*0Sstevel@tonic-gate }
101